Human Error Severity Evaluation

The importance of each element (derrick, vessel, lazy decky, net and Gilson) is determined using the comparison scale in Table 9.7. The matrix below is obtained for the severity importance of each element. 

The weighting vector and normalised vector are determined by considering the weighting vector obtained in the Level Two matrix and are shown as follows  

The matrices for the severity of the consequences of human error for each task are determined as follows  

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After you record the steps of the job, review each step to determine the hazards that exist or that might occur. There are several ways to identify job hazards evaluate the ways human error might contribute to a hazard, record the types of potential incidents and the physical agents involved, and make sure that procedures are clearly written. 

Measures to reduce human error are often implemented at an existing plant, rather than during the design process. The decision to conduct an evaluation of the factors that can affect error potential at an existing plant may be taken for several reasons. If human errors are giving rise to unacceptable safety, quality or production problems, plant management, with the assistance of the workforce, may wish to carry out a general evaluahon or audit of the plant in order to identify the direct causes of these problems. 

Several examples have already been provided of the use of cognitive models of error to evaluate the possible causes of accidents that have already occurred. This form of retrospective analysis performs a vital role in providing information on the recurring underlying causes of accidents in which human error is implicated. The advantage of an analytical framework driven by a model of human error is that it specifies the nature of the questions that need... 

Human error tmalysis (HEA) is a systematic evaluation of the factors tliat influence tlie performance of human operators, maintenance staff, teclmicians, and otlier persomiel in tlie plant. HEA involves the evaluation of one of several types of task analysis, which is a metliod for describing tlie physical and enviromiiental characteristics of a task along witli tlie skills, knowledge, and capabilities required of tliose who perform the task. Tliis type of analysis can identify error-likely situations tliat can cause or lead to an accident. 

Several qualitative approaches can be used to identify hazardous reaction scenarios, including process hazard analysis, checklists, chemical interaction matrices, and an experience-based review. CCPS (1995a p. 176) describes nine hazard evaluation procedures that can be used to identify hazardous reaction scenarios-checklists, Dow fire and explosion indices, preliminary hazard analysis, what-if analysis, failure modes and effects analysis (FMEA), HAZOP study, fault tree analysis, human error analysis, and quantitative risk analysis. 

Techniques for the identification and evaluation of human error are typically labeled Human Reliability Assessments (HRA). A complete HRA starts with a definition of the problem and development of a task analysis to support the HRA (Kirwan, 2005). The core of HRA is the Human Error Identification (HEI) and Human Error Quantification (HEQ) stages, and several methods have been developed to specifically focus on these two areas. From these, control measures can be identified to reduce the overall system risk. 

Finally, it is important to realize that geochronologists do not rely entirely on error estimates or fits to lines on correlation diagrams to evaluate the accuracy of radio-metric ages. The simplest way to check the reliability of an age measurement is to repeat the analytical measurements in order to minimize analytical errors. This procedure helps to minimize human error and also provides information on which to determine analytieal preeision. Another teehnique is to measure ages on several samples (rocks or minerals) from the same roek unit. This technique helps to identify geological factors because dif-... 

The NMR methods have been used in clinical medicine for many years, and metabonomic evaluation of human samples has been conducted for at least the past 10 years (28). Classical examples include the application of NMR to the evaluation of inborn errors of metabolism (29). More recent work has applied metabonomics to the evaluation of the clinical severity of coronary artery disease and to establish a relationship between serum metabolic profiles and hypertension (30,31). Because metabonomics is highly sensitive to environmental or dietary influences (discussed under toxicological applications), concern has been raised that the natural variation in the human population would preclude the application of metabonomics to clinical problems. However, such concerns have been dealt with directly, and recently, Lenz et al. (32) demonstrated that urine and plasma could be collected from human subjects and used successfully for metabonomic analyses. Furthermore, in addition to the disease states described above, metabonomics has been shown to a potentially useful tool for describing alterations associated with dietary and nutritional practices (33). 

US NRC (2000) also raised several human performance issues associated with CBPs. The issues are as follows methodological and criterion requirements for evaluating CBP effects, role of plant personnel in procedure management, team performance, situation awareness, response planning, and operator error level of automation of procedure functions keyhole effects and use of multiple CBP procedures CBP failure in complex situations hybrid procedure systems and specific CBP design features. 

In evaluating food requirements in infancy, one must consider that the infant s enzymic arsenal is not equivalent to that of the adult. We have already mentioned that in guinea pigs and rats, glucose-6-phospha-tase is practically nonexistent until shortly before term, but after term it rises rapidly. In humans, phenylalanine hydroxylase is absent from liver until several weeks after term. If the formation of the enzyme molecules is completely inhibited because of a genetic defect, an inborn error of metabolism develops. In rats, tyrosine transaminase increases immediately after birth and reaches a maximum 12 hours after birth. 

Another sign of development is that a growing number of thermokinetic parameters are accompanied by estimations of their accuracy. In the best cases, these uncertainty estimates are based not on the error analysis of a single experiment but reflect the comparison of several independent experimental or theoretical studies and therefore incorporate systematic errors of the various methods. In the past, such evaluations were performed by human experts, but as the dataset grows, perhaps a new paradigm for this process is required. Data collaboration approaches have been suggested which could place this task in the hands of wide communities (and computer software), rather than small groups of experts. 

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